1. Field of the Invention
The present invention relates to a quick release extension rod, and more particularly to a quick release extension rod with a positioning structure.
2. Description of the Prior Art
FIGS. 1A and 1B show a conventional quick release extension rod A, a body 10 of the extension rod A is formed at the end thereof with a connecting head 11, between the connecting head 11 and the rod is connected a positioning control device 12. The connecting head 11 is formed in a lateral surface thereof with a positioning hole 111 in which being disposed a ball 112. A pin 13 is inserted in the connecting head 11, one end of the pin 13 is formed with an avoiding groove 131 located corresponding to the positioning hole 111 of the connecting head 11, and the other end of the pin 13 is connected to the positioning control device 12. Pushing the positioning control device 12 can selectively make the avoiding groove 131 of the positioning control device 12 be misaligned or aligned with the positioning hole 111 of the connecting head 11, so that the ball 112 will be connected to or disengaged from a socket B by projecting into an engaging cavity B1 of the socket B or retracting into the positioning hole 111.
It is to be noted that the operation of the conventional quick release extension rod A is such that when the socket B is connected to a work head, the body 10 is driven manually or by power means to rotate the socket B, and meanwhile, the socket B rotates the work head. Therefore, the reliability of the connection between the socket B and the quick release extension rod A is very important to the working efficiency of the extension rod A driving the work head.
However, as shown in FIG. 1B, the axial direction of the body 10 of the extension rod A is defined as X, and the radial direction perpendicular to the axial direction X is defined as Y. A radial interval S1 is left between the socket B and the connecting head 11 of the quick release extension rod A after they are jointed to each other, and there is also an axial interval S2 left between the socket B and the positioning control device 2. When the quick release extension rod A is locked to the socket B by the ball 112 and rotates, the center of gravity of rotation of the socket B is likely to be asymmetrical, which will increase the centrifugal force of the socket B and result in oscillation.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.